Automatic transmission-band adjuster



March 4 1924,.

H. J. ZflfifiiERMAN AUTOMATIC TRANSMISSION BAND ADJUSTER w Filed Sept.5, 1926 Aiimn @y the upper ends of hicle, having 'pedalaction therebyproduciru inward Patented lldsrq d, @924.

I 194855752 FFIEG.

AUTOMATIC TRANSMISSION-BANK) ADJUSTJ EB,

Application filed September a, me. Serial n comes To all whom it mayconcern:

Be it known that I, HARRY J. ZIMMERMAN, citizen of the United States ofAmerica, residing at Pekin, in the county of Tazewell and State ofIllinois, have invented certain new and useful Improvements in AutomaticTL'111SI11lSSlOl1BE1I1(l Adjusters, of which the following is aspecification.

My invention relates to automatic transmission band adjusters, and isadapted-more particularly for use with Ford transmission bands.

The object of the invention is to produce an automatic transmission handadjuster of simple, durable and inexpensive construction.

Another object of my invention is to produce a device capable of beingused in conjunction with the usual transmission band controllingmechanism, said device automatically taking up the wear on the bands anddoing away with all ordinary means therefor.

With these and other objects in view, my invention consists in theconstruction, arrangement and combination of parts of the device ashereinafter more fully set forth. In the accompanying drawings, Fig. 1is a perspective View of a gear casing mounted in a motor vehicle, aportion broken away in order to show my automatic hand adjuster;

Fig. 2 is an end elevation of the device;

Fig. 3 is a front elevation of the same;

Fig. 4'. is a rear view of the ratchet memher Fig. 6 is a front view ofthe key.

The construction is as follows:

A represents a gear casing on a motor vethe transmission mounted within.Foot pedal 2 has t e customar cam surface connection? with the threa edshaftb which rides in the hearing l, and outward movement of the shaft.A broken hand 6 surrounds a drum.7, and end members 8 mounted on hand 6are til-slotted on their upper ends to take therein the shaft 5. A coilspring 10 surrounds the shaft, ano abuts the end members. on the shaft 5by the lug 5 is a side view of the keymemher,

member 11 is keyed i2 and corresponding groove 13 on the shaft. is lugl4: progectmg from the key ll Fits into a corresponding recess 15 on ascrew member adjustment caring threaded ratchet member 16 screwed on theinner end of shaft5.. Riding on the ratchet 1s a pawl 17,pivotally-mounted at 18 on the bracket 19,,said bracket'having at itsbase a hole for the entrance of the shaft, and a lug 20 projecting fromits rear to intersect the upper portion of groove 21 on the end 8,thereby providing a secure mounting for the pawl. A. coil spring 22 isheld in operable position by the lug 23 on the pawl 17 and a groove 24on the under side of the bracket-19.

The operation of the device is as fol lows :-A. downward pressure of theedal causes a tighteningofjthe transmission and 6 on the drum 7, throughthe cam surface connection which draws the shaft 5 inwardly, and arelease of the pedal causes the coil spring 10 tothro'wj the hand out ofengagement with the druni when the shaft 5 has been released and movedoutwardly. In order to more clearly describe the operation of thedevice, we will say that the brake band has been worn considerably andis loose on the drum f. When the'pedal is pressed downwardly the shaft 5moves in a clockwise manner and inasmuch as it is drawn inwardly, due tothe cam surface connections, the ratchet member 16, key 11, bracket 19,and the end members 8 or portions thereof, are all jammed together; Asthe'shaft 5 turns slightly in its clockwise movement, it turns with itthe key 11 which rotates with said shaft, due to its keyed relation.therewith and inasmuch as the ratchet member 16 has-been thrown intofrictional contact with said hey due to the tightening action of thepedal and also tension of coil sprin '10, this ratchet member is alsoturns with a movement to correspond with that of key 11.

It may beseen, here that the frictional contact between the ratchetlfiand key 11 is all that is necessary to permit this correspondingtightening'of the ratchet member or turning to correspond with that ofthe key member. However, in'view'of the fact that this device is mountedwithin the transmission casing ofan automobile and as there isconsiderable oil and grease therein, an additionalmeans is provided forinsuring this tightening of the ratchet member oil overcome the frictionthat is set up between the ratchet member and key. This is accomplishedby providing a raised pnoiection or lug l4 oaths key 11 and a pluralityshould the of recesses 15 in the ratchet member. To continwe with theoperation of the device, after the pedal has been thrust downwardly andthe ratchet member .and key member turned .to correspond with shaft 5,inasmuch as theband, as has been stated, is loose on the drum, theratchet member will move'a distance beyond one of its ratchet teeth withi the result that when it'is'moved this far,

the pawl 17 will dro behind said tooth and prohibit an anti-cloc wisemovement of the ratchet member when the pedal has been released and theshaftb carrying the key 11 moved in an anti-clockwise manner. Thus itwill be seen with the release of the pedal,

' the frictional engagement of the key 11 and ratchet 16 will berelieved and the key memher, due to its keyed relation with the shaft 5,will move in an anti-clockwise movement- ,but not the ratchet member.

The.;tightening action which accompanies onempvement of the pedalwhenthe brake band is very loose, has just been described,

a and it will be readily understood that this yond the len h of one, ofthe teeth, with the move the ratchet member under the not made to startwith, however, it is clear 7 that the device may be put on the shaft 5,

result there ore, that until the band has been worn'considerably, thepawl will not engage a new tooth. However, when the band has been wornto this degreefthe pawl will engage a new tooth on the ratchet member. Atightening will have taken place to compensate for. the wear on the bandand a ain a similar movement back and forth the pawl on one of theseteeth will'take place until the band has beenworn again't'o such a pointthat it will need tightening.

Thus, we will see that the tightener is pos1-' .tively automatic, andworks in a gradual manner to take up the. wear on the bands;

The operation of the devicehas beensq far described with the idea ofshowing that the device, when placed upon the end of the shaft 5, willtighten the band automatitally even though the correct adjustment is.

screwed to the efii'cient adjustable point and] thence will actautomatically to take up the band from that point. m 4 'To more clearlybring out the actioniof; the key and its relation to the ratchet mom]?'ber's, a foot pedal havlng a beveled hearifig ber, with'the pedalaction and the turning of the shaft 5 in a clockwise position, the keymember will be forced into frictional engagement with the ratchet memberand will turn said ratchet member not only by thefriction set up betweenthese two elements which is sufficient, but by the lug 14 which haspossible engagement with one ofthe plurality of re- 7 I cesses 15 intheratchet member. Also with the release of. the pedal the frictional.en-

agement of these members is relieved and t e key .slidesin ananti-clockwise manner and also the .ratchet'membeuwill have ananti-clockwise movement, unless the band is so loose that the pawlengages a new tooth and tightens-fthe band. However, when the band hasbeen adjusted to its most efficient point, there will be a tighteningaction on 'the.ratchet member, we will say, only once in 500 or 1,000times to compensate for the wear on the band, and therefore the ordinarymovement Will be that the ratchet member moves in an anti-clockwisemovement to agree with the movement of shaft 5, said movement not. beingordinarily suflicient to have the pawl engage a new tooth on the ratchetmember. 'As pressure is applied to the pedal the key will be forced intofrictional engagement with the ratchet member and will turn' it;however, as the pedal is released, the key will rotate in ananticlockwise manner and also the ratchet will have an anti-clockwisemovement under the pawl which will merely ride on theupper surface oneof these teeth, but will not engage a new tooth.

Briefly the general movement, we see, is

' that the ratchet member upon pressure and release of the pedal slidesunder this pawl but" not to such an extent that a new tooth will beengaged by the awl until the band has become worn to sue an extent thatthe pedal will move far enough downward to permit the pawl to engage anew liOOtlLgOIl the ratchet member. This, a series of peda movementswill again have to take place will be another tightening of the band ana 'wearing of the brake band before Thus we may see that with thedevieede- I scribed an automatic means has been; rovided to compensatefor the wear onaihto en brake band mounted on a drum.

\Vhat is claimed is: 1. The combination of a drum, bandathereon, havinprojecting end mom surface, a shaft connected to said foot pedal andextending through the end members, a

spring between said end members, a ratchet 1 member on said shaft, abracket mounted on the inner end member, and a spring pressed pawlpivotally mounted on sald bracket in engagement with said ratchet.

f 2. In combination with a transmission easing, a shaft mounted thereinand brake band, a block slidably mounted upon said shaft and heldagainst rotation by ongagement with one of said holding brackets, aratchet nut threaded upon said shafti.

and a pawl swingingly mounted upon sai block and adapted to engage theteeth of said ratchet nut. i

4:. In combination with atransmission casing, a pedal shaft mountedtherein and carrying'upon one end a pedal, a drum an open bandsurrounding, said drum, holding brackets loosely mounted upon said shaftand attached, respectively, to opposite ends of said band, a blockslidably mounted upon said shaft, and held against rotation, a I

combmatmn w1th the forked end of the ratchet nut threaded upon saidshaft, and a pawl swiugingly mounted upon said block and adapted toengage the "teeth of said ratchet nut.

5. In combination with a transmission casing, a pedal shaft mountedtherein and carrying upon one end a pedal,'a block slidably mounted uponsaid shaft and held against rotation, a Washer also slidably mountedupon said shaft and provided with an inwardly extending tongue engaginga slot in said shift, a, ratchet 'nut threaded upon said shaft, and apawl mounted upon said block. and adapted to engage thejteeth of saidratchet nut.

6. In combination with a transmission casing, a pedal shaft mountedtherein and carrying upon one end a pedal, holding brackets looselymounted upon said shaft and attached, respectively, to opposite ends ofa brake band, a block slid'ably mounted upon said shaft and held againstrotation by engagement with one of said holding brackets, a washer alsoslidab-ly' mounted. upon said shaft, and provided with an in,- a slot insaid shaft, a ratchet nut threa ed upon said shaft, and apawl swinginglymounted upon said block and adapted to engage the teeth in said ratchetnut. 7. In' combination with the transmission means of a motorvehicle,;a pedal shaft, and a transmission band, of ratchet mechanismconnected with the pedal shaftand a part of the transmission band forautomatically taking up "the slack 'of 'the band by the movement of thepedal. g v 8. In combination with the transmission means of a motorvehicle, a pedal shaft,

nut.

and a transmission band, of ratchet mechanism connected with the pedalshaft and a part of the transmission band for automatically taking upthe slack of the band by the movement of the dal, such means consistingof a ratchet w eel screw threaded on the pedal shaft-and a pawlconnected combination with the forked end of the band and the shaftdisposed therethrough, of a member on one end of the shaft and havingmeans engaged in the forked end of the band, a ratchet nut on the shaft,and a with a part of the transmission band and pawl on the said memberengaged with the 11. In a transmimion band adjuster, the

- spring or expanding said band, means for contracting said band so asto produce a brakmg action, said means 'comprism a bolt joining the two.ends of said ban a.

nut on the end ,of said bolt, means for rotating said boltandsimultaneously movin the same inthe direction of its axis an meansfor rotating said nut so as to bring the ends of the band close togetherwhenever the rotary movement of the bolt exceeds a predetermined amount.

13. An automatiomeans for ad'usting a brake band so as to compensate orwear, comprising a bolt, a nut'co-operating therewith, a membersurrounding said bolt, a pawl on said member, a spring tendin jectingportion on saidwasher adapted to engage said groove. to prevent thewasher from rotating on the bolt, saidnut having a series of ratchetteeth adapted to co-operate with the pawl.

In testimony whereof I have'afiixed my signature. I

I v, HARRY J. ZIMMERMAN.

tomove the end of said pawl towards the olt,

iis'

